FIG. 12 is a side view of a front part of a vehicle of related art, and shows a front grill 102 covering the front of an engine compartment 101 provided at the front of a vehicle 100, and a water-cooled engine radiator 103 housed in the engine compartment 101 in the rear of the front grill 102.
The water-cooled engine radiator 103 has a lower part 103a attached to a lower front part 105a of a vehicle body frame 105 and an upper part 103b attached by a stay 104 to an upper front part 105b of the vehicle body frame 105. 106 is a hood.
When a collision force F10 acts on the front grill 102 from the front, the front grill 102 deforms in correspondence with the collision force F10; that is, it retreats. By the retreating front grill 102 striking the radiator 103, the collision force F10 is transmitted to the radiator 103. And by the radiator 103 deforming and tilting rearward under the collision force F10, the collision force F10 can to some extent be absorbed.
Now, the distance L10 from the front grill 102 to the radiator 103 is set so that a travel motion draft taken in through the front grill 102 can be guided smoothly to the radiator 103. Accordingly, there is a limit to how small the distance L10 can be made.
On the other hand, for the collision force F10 to be absorbed by the radiator 103 more swiftly and more fully, it is desirable that the collision force F10 be transmitted to the radiator 103 in the initial stage of the front grill 102 retreating under the collision force F10. This is because in this initial stage the collision force F10 is relatively small, and consequently it is possible to protect the various devices inside the engine compartment 101 and also moderate the impact on the obstruction.
The various housed members such as the radiator 103 housed in the engine compartment 101 are disposed like this in positions where their respective capabilities can be secured. With respect to this, the disposition and shape and size of the front grill 102 are decided with matters such as the design of the vehicle 100 overall also being considered. Consequently, there is a limit to how small it is possible to make the distance L10 between the front grill 102 and the various housed members.
Accordingly, there is a need for technology by which, when a collision force acts from the front on the front grill, it is possible to absorb the collision force more swiftly and more fully.
Next, a mounting structure of a radiator of a water-cooled engine of related art will be explained.
Generally, a water-cooled engine radiator disposed at the front of a vehicle is removably mounted to a vehicle body frame. Amounting structure of a water-cooled engine radiator of this kind will now be described on the basis of FIG. 13A and FIG. 13B.
FIG. 13A shows a lower part 201 of a radiator 200 for a water-cooled engine attached to a front-lower part 211 of a vehicle body frame 210, and an upper part 202 of the radiator 200 attached by way of a stay 203 to a front-upper part 212 of the vehicle body frame 210.
More specifically, as shown in FIG. 13B, a mounting structure for the upper part of the radiator has a stay 203 extending rearward from the top face of the radiator 200 and the its end attached to the front-upper part 212 of the vehicle body frame 210 by a bolt 213. By means of the stay 203 it is possible to suppress vertical movement of the radiator 200 and prevent leaning. To enable it to suppress vertical movement of the radiator 200, the stay 203 is a member with a relatively large bending rigidity, provided with multiple vertical ribs 204.
However, in the related art technology described above, because the upper face of the radiator 200 is just supported by the stay 203, there is room for improvement in the degree to which vertical movement of the radiator 200 is suppressed at times such as when the vehicle is traveling on a rough road.
And, when a collision force F10 acts on the front grill 220 from the front, as shown in FIG. 13A, the front grill 220 retreats and strikes the radiator 200, as shown with broken lines in FIG. 13A. As a result, the collision force F10 acts on the stay 203 by way of the radiator 200. And because the stay 203 has a high rigidity, as mentioned above, it can withstand even a large collision force F10. Consequently, the collision force F10 cannot be expected that much to be absorbed by the radiator 200.
For this reason, technology has been wanted by which vertical movement of a water-cooled engine radiator can be suppressed and by which also, when a collision force acts on a water-cooled engine radiator from the front, the collision force can be fully absorbed.